1. Field of the Invention
The present invention relates to a capturing device and a method for shutting down; in particular to a method for shutting down a timing generating unit, a method for shutting down a digital image-capturing device, and a digital image-capturing device.
2. Description of Related Art
Digital image-capturing device (such as a digital camera) provides a fast and convenient way for a user to take pictures, but as various digital image-capturing device becomes more common, users are becoming more particular over the requirement and functions of these digital image-capturing devices. For example FIG. 1 is a function block diagram of a digital image-capturing device according to the prior art, which has the following shut down procedures:
First, once the control unit 90 receives the message that the digital image-capturing device 9 is shutting down, then the control unit 90 outputs a signal so as to shut down the timing generating unit 92. Therein, from the point of view of the timing generating unit 92, it immediately shuts down upon receiving the signal from the control unit 90. Therefore at this time, under normal condition, the driving unit 94 is no longer able to receive the pulse signal for the driving operation of the imaging device 96 (such as a CCD or a CMOS) from the timing generating unit 92. The end result is that the imaging device 96 can be successfully shut down without damage from the pulse signal.
However under certain circumstances, such as shown by FIG. 2, damages may occur to the imaging device 96. Therein, when the control unit 90 outputs a signal at time Ti for controlling the shut down of the timing generating unit 92, then the timing generating unit 92 shuts down immediately, however the vertical pulse (V_Pulse) signal being output by the timing generating unit 92 is at the highest voltage level. Therefore, although the timing generating unit 92 is being shut down, the voltage level of the vertical pulse signal output by the timing generating unit is still retained at a high voltage level. Furthermore, at this time T1, the shutting down of the voltage VH/VL that is used for the operation of the imaging device 96 also occurs, yet because the discharge time for this voltage VH/VL is not fixed, therefore the shut down is not immediately, and the end result is that the retained high voltage level from the timing generating unit 92 may cause damages to the imaging device 96 through the driving unit 94.
Therefore the conventional method of shutting down the digital image-capturing device 9, is primarily through the control unit 90 controlling the time of shut down for the timing generating unit 92, however from the point of view of the control unit 90 there is no information regarding operation status of the timing generating unit 92 at this time of shut down. For example, the control unit 90 cannot determine whether or not the vertical pulse signal output by the timing generating unit 92 is at a high voltage level; so that when shutting down, it is very likely for the imaging device 96 to receive the high voltage retained from abnormal shut down of the timing generating unit 92, and thereby damaging the service lifespan of the imaging device 96. Therefore, how to provide protection for the imaging device 96 from damage is an issue that needs to be resolved.